1. Field of the Invention
This invention relates to Stirling cycle devices, specifically linearly driven single- and multi-cylinder Beta type devices.
2. Description of the Prior Art
Stirling cycle devices are well-known, and are operable as engines or heat pumps. Thermodynamic properties of a working gas contained within the device are exploited by compression, expansion, heating, and cooling, according to the Stirling thermodynamic cycle of the working gas, wherein more energy is obtained from the expansion of a heated quantity of gas than is required to compress the same quantity of gas that is cooled.
When the device is operated as an engine, its basic function is to convert a thermal differential to rotational energy. A thermal differential is externally provided between two physical portions of the device, and the shaft rotates. In this mode, the device is an engine.
When the device is operated as a heat pump, its basic function is to convert rotational energy of a shaft to a thermal differential. The shaft is rotated by external means, and the device produces a thermal differential between two physical portions of itself.
(For simplicity, unless otherwise noted, this narrative assumes that the device under description is being operated as an engine, and it is understood that the device could be operated as a heat pump by reversing operation. Conversely, if heat pump mode is being described, it is understood that the device could be operated as an engine by reversing operation.)
Many techniques have been developed to increase the effectiveness of the Stirling cycle device. Usually these techniques involve excessive mechanical linkages or size, exotic materials, and unusual construction methods. Although effectiveness may be improved, expense and complexity are increased, which reduces the device's viability.
U.S. Pat. No. 5,394,700, “Stirling Engine with Ganged Cylinders and Counter Rotational Operating Capability”, inventor Steele, is hereby incorporated by reference.